1. Technical Field
The present invention relates to page receivers and more specifically, to a page receiver operable in a multichannel radio system.
2. Description of the Prior Art
Radio paging systems are well known in the art. These systems typically comprise a radio transmitter for transmitting a coded paging signal representative of the party being paged and a mobile pager for notifying the designated party that he or she is being paged. The radio transmitter is accessible via the public switched telephone network to a person who wishes to reach a party carrying a pager. To reach the designated party, the person dials a telephone number which identifies the party to be paged and causes the coded page signal to be generated. Once the page signal is generated, the radio transmitter is activated and the paging signal is transmitted to all mobile pagers which are within the range of the transmitter. Each mobile pager is coded to respond to a different paging signal so that only the pager having a code corresponding to the code on the transmitted paging signal is activated. The pager responds to its corresponding paging signal by emitting an audible tone or some other appropriate signal. Upon receiving the notification of a page, the designated party responds by following a prearranged course of action, such as calling a specific telephone number to receive further instructions.
Present radio paging systems having effective ranges which vary considerably. The effective range of a radio paging system is dependent upon many factors with one of the most determining factors being the distance between the radio transmitter and the paging receiver. To increase the reliable range of a radio paging system, it is possible to use more than one radio transmitter strategically located within the paging service area. With this arrangement, a paging receiver has a higher probability of being activated by a signal from one of the radio transmitters.
There is increasing interest in expanding the availability of paging to beyond the local paging service area served by a few transmitters. Several methods have proposed for providing such a paging system. One method for expanding paging coverage beyond a single paging service area would be to provide each customer with more than one telephone number which could be dialed to reach the subscriber. Each phone number would be assigned to the subscribed and located in a different paging service area.
Another proposal for providing nationwide paging involves employing a master transmit station to communicate pages to and from several base stations employing a type of hub and spoke arrangement. Subscribers may move freely from one paging service area to another and transfer their paging service. While the subscribers are in transmit, pages are automatically stored. If the subscriber is paged during the transit period, he is paged when his paging service is transferred upon arrival at his destination area.
Still another proposal for providing a nationwide paging system involves employing a multiple frequency receiver which receives special coded message signal reflecting that a page message is being sent on a local frequency. In the absence of the special coded message signal, the receiver is programmed to switch to a different designated nationwide frequency for receiving the page message.
Although each one of the above systems provide reasonable widespread radio paging services, each system requires a break in paging service as a subscriber moves from one paging service area to another or cumbersome techniques for effectuating the required transfer of the paging service. Each system would also appear to require considerable investments for any future expansion in addition to being technologically limited if future demands for more comprehensive subscriber facilities and services continue. It is therefore desirable to have a pager suitable for operation in a system providing sophisticated facilities which allow for continuous paging service and economy to subscribers while allowing unlimited adaptability and expansion for effectuating a nationwide paging capability.